Switch construction having improved contact and bracket assembly



Oct. 12, 1965 BENGTSSQN 3,211,874

SWITCH CONSTRUCTION HAVING IMPROVED CONTACT AND BRACKET ASSEMBLYOriginal Filed Nov. 14. 1961 INVENTOR. BFRT/L S. BENGTSSON BY %w, 71- 1%a 702%) A T TORNE Y5.

United States Patent Claims. Cl. 200-166) This is a division ofapplication Serial No. 152,261, filed Nov. 14, 1961.

This invention relates to electromagnetic devices and particularly tothe construction of contact supporting brackets and contacts for relayssuitable for general industrial use. Broadly stated, the objects of theinvention are to provide a relay having long life, high switchingcapacity, high reliability, low manufacturing cost, and of suchdimensions and characteristics as to be interchangeable with the largestnumber of competitive relays intended for use under comparableconditions.

A more specific and very important object of the present invention is toeliminate as far as possible the internal Wiring in the relay. Much ofthe available space inside the relay envelope has, in priorconstructions, been occupied by wiring between the terminals of therelay proper and its base or plug-in termination. The wiring which hasbeen heretofore required, aside from being space-consuming, is costly,and many solder points are required which are a constant source oftrouble, possible breakdown and increased resistance. In theconstruction of the present invention most of the internal wiring andsoldered joints are eliminated. It has thus been possible to utilize theavailable space in the relay envelope so that, without enlarging overalldimensions, it has been possible to lengthen the flexible members of theswitches, thus permitting a larger cross section for a given springcharacteristic. This has made possible reduction of the total contactresistance of the relay, terminal to terminal. This decrease inresistance is in addition to that secured by the elimination of many ofthe soldered joints required in previous constructions.

An important feature of construction which is preferably embodied in thestructure of the present invention is the formation of various parts soas to include within the parts themselves fastening means by which theparts may be assembled. These formations cooperate with formations onother parts and particularly with spring clips by which the parts may besecured. The use of welding or soldering in joining parts is minimizedand conventional fastening means such as screws, bolts or rivets arewholly or largely eliminated. Valuable space is thus saved, the expenseand nuisance of handling many small parts is reduced, and the danger ofscrews and nuts becoming loosened during use is avoided.

Other objects and advantages of the invention will appear in the courseof the following description of a preferred embodiment thereof. One suchpreferred embodiment is illustrated in the accompanying drawings. Thesedrawings show a double pole double throw electromagnetic relay which maybe provided in forms for either AC. or DC. operation. Many features ofthe invention are obviously applicable to other forms of relay and someof the features are useful in connection with other types ofelectromagnetic or switching apparatus. The applicability of the variousinventive features disclosed is therefore not to be taken as limited tothe particular type of relay illustrated.

FIG. 1 is a top plan view of the terminal pin base with the relay baseassembled thereon and having contact ice brackets carrying their contactelements constructed in accordance with the invention;

FIG. 2 is a vertical section on line 2-2 of FIG. 1 showing the relaybase mounted on the pin base;

FIG. 3 is a side elevation of the contact terminal bracket;

FIG. 4 is a fragmentary view in rear elevation of the upper part of thevertical arm of the contact terminal bracket shown in FIG. 3;

FIG. 5 is a side elevation of the relay shown in FIG. 1;

FIG. 6 is a side elevation of one of the spring contacts before beingassembled; and

FIG. 7 is a front elevation of the same.

Referring to the drawings in detail, the illustrated embodiment of theinvention is a double pole, double throw relay. The relay embodies abase 50 of insulating material carrying terminal pins 52 and 52aarranged to fit in a conventional socket (not shown). Mounted on thebase are a pair of normally open contacts 54 and normally closedcontacts 56. These are engaged alternately by movable contacts 58carried on contact springs 60. The contact springs are actuated by apivoted armature 62 moved by an electro-magnet having a core 64surrounded by a coil 66. When the coil is de-energized the armature ismoved away from the pole face of the core by armature tensioning springs68 so that the movable contacts 58 engage the normally closed contacts56. When the coil is energized, the armature moves so as to relieve thepressure on the springs 60, which are prestressed so as to move thecontacts 58 into engagement with the normally open contacts 54.

A novel construction of base is provided in which soldered connectionsare eliminated and also the use of screws and bolts.

The base is made in two pieces of insulating material such asthermo-setting phenolic plastic. The lower of these pieces, 70,comprises a pin base from which the terminals 52 and 52a project, whilethe upper piece 72 may be termed the relay base. The pin base is shownas having a guide pin 71 molded integral therewith. On the pin base aremounted the brackets 74 carrying upwardly projecting arms 76 to whichare fixed the movable contact springs 60. Also carried by the pin baseare the brackets 78 carrying the normally closed contacts 56. Thebrackets 78 are separated from the brackets 74 by pieces of insulatingmaterial 82 (FIG. 2). Mounted on the relay base are brackets 84 carryingthe normally open contacts 54. The pin base has a flange or shoulderportion 86 in which lugs 88 on the relay base fit. The pin base 70 andthe relay base 72 and brackets 84 are all permanently clamped togetherby certain of the terminal pins 52, which are provided midway theirlength with flanges 90 fitting in sockets 92 in the bottom of the pinbase and which have shank portions 94 extending through holes in the pinbase 70 and up through matching holes in the relay base 72. The upperends of the shanks are spun or flanged over as indicated at 96. Therelay base is narrower than the pin base terminating at the line 98(FIG. 1) so as to leave a space through which projects upwardly thespring-carrying bracket portions 76 and the contact-carrying portions 78which carry the contacts 56. The brackets 78 are clamped against theinsulating pieces 82 which, in turn, bear on the bracket 74, these partsbeing held in firm contact by pins 52a, the shanks 94a of which areshorter than the shanks 94 of pins 52.

The shanks of the terminal pins are of such diameter in relation to thesizes of the holes in the respective terminal brackets mounted thereonthat the shanks have to be forced through the holes with substantialpressure. The force fit thus obtained insures good electrical contactwithout soldering. The shank diameter should be sufiiciently larger thanthe hole diameter to result in substantial stressing of the metal sothat a tight contact is maintained under all temperature conditions towhich the instrument will be subjected.

The contact springs 60 are of inverted U shape having legs 126 which arefixed to the arms 76 of the brackets 74. The arms 76 are shown asprovided with holes 128 which receive outwardly bent lugs 130 on thelower ends of the spring legs 126. The arms 76 also have tongues 132(FIGS. 3, 4) bent inwardly near their upper ends, and the spring legs126 have tongues 134 (FIGS. 6, 7) bent outwardly so as to slide behindthe tongues 132. The springs are thus held firmly by slipping thetongues 134 into position and the lugs 130 into the holes 128. The longouter legs 136 of the contact springs have fixed to their ends themovable contacts 58.

In devices of the lower ratings where current values are not too great,the mounting of the contact springs by means of the lugs and tonguesdescribed, forms a low resistance connection so that no other fasteningmeans between the springs and the arms 76 of the brackets is required.This is advantageous because the assembly is very quickly effectedwithout the use of any special tools and also the contact springs may bereadily detached from the brackets for adjustment or replacement. Wherehigh currents are involved, it may be desirable to weld or solder thesprings to the brackets. In this case, the lug and tongue connectionsdescribed facilitate the welding and soldering by holding the springs inproper position during such operations.

The base section comprising the pin base, relay base, pins carriedthereby which also secure the base parts together, the fixed contactbrackets and movable contact brackets and springs carried thereby,constitute a complete sub-assembly (FIG. 2) which may be put together byspinning over the ends of the pins as above described (and by weldingthe contact springs to their brackets, where this is needed).

While but one specific embodiment of this invention has been shown anddescribed in detail, it will be understood that many variations may bemade in the construction and that many features of the invention arecapable of being used without others in different types of devices. Itis desired, therefore, to cover the invention in whatever form itsprinciples may be embodied.

I claim:

1. In an electro-magnetic switch construction, a contact supportingbracket and a U-shaped contact spring supported thereon, said bracketand spring having fiat portions arranged in juxtaposition and beingprovided with integral interlocking tongue formations on said flatportions for solely supporting and removably holding said spring infixed position on the bracket.

2. A construction as claimed in claim 1 in which the interlocking tongueformations include inclined overlapping tongues bent from the bracketand spring respec tively.

3. A construction as claimed in claim 2, in which one of said bracketand spring members has a hole formed therein and the other of saidmembers has a lug on said fiat portions at a spaced location from saidtongue formations engaging said hole so as to prevent removal of thespring from the bracket without first disengaging said lug from saidhole.

4. In a switch construction, a contact supporting bracket having aportion with a projecting bracket tongue extending obliquely outwardlytherefrom and with an opening defined in said portion adjacent saidtongue, a contact spring having a portion with a spring tongue extendingobliquely outwardly therefrom in a direction opposite to said brackettongue and engaged over said bracket tongue and into the opening definedin said bracket portion adjacent said bracket tongue, said contactspring being supported on said bracket solely by interengagement of saidbracket tongue and said spring tongues.

5. In a switch construction, a contact supporting bracket having aportion with a projecting bracket tongue extending obliquely outwardlytherefrom and with an opening defined in said portion adjacent saidtongue, a contact spring having a portion with a spring tongue extendingobliquely outwardly therefrom in a direction opposite to said brackettongue and engaged over said bracket tongue and into the opening definedin said bracket portion adjacent said bracket tongue, said contactspring being supported on said bracket solely by interengagement of saidbracket tongue and said spring tongues, said bracket having an-openingdefined therein at a spaced location from said bracket tongue, saidcontact spring having a projection extending into the opening of saidbracket for preventing removal of said contact spring from said bracket.

References Cited by the Examiner UNITED STATES PATENTS 2,769,881 11/56Hailes 200166 2,967,216 1/61 Zablocki et al. 200166 X 3,076,063 1/63Prace et al 200166 X 3,102,933 9/63 Berthier 200166 X BERNARD A.GILHEANY, Primary Examiner.

1. IN AN ELECTRO-MAGNETIC SWITCH CONSTRUCTION, A CONTACT SUPPORTINGBRACKET AND A U-SHAPED CONTACT SPRING SUPPORTED THEREON, SAID BRACKETAND SPRING HAVING FLAT PORTIONS ARRANGED IN JUXTAPOSITION AND BEINGPROVIDED WITH INTEGRAL INTERLOCKING TONGUE FORMATIONS ON SAID FLATPORTIONS FOR SOLELY SUPPORTING AND REMOVABLY HOLDING SAID SPRING INFIXED POSITION ON THE BRACKET.